Definition of "Sink" :

noun: a covered cistern; waste water and sewage flow into it

noun: plumbing fixture consisting of a water basin fixed to a wall or floor and having a drainpipe

noun: a depression in the ground communicating with a subterranean passage (especially in limestone) and formed by solution or by collapse of a cavern roof

noun: (technology) a process that acts to absorb or remove energy or a substance from a system

"The ocean is a sink for carbon dioxide."

verb: fall heavily or suddenly; decline markedly

verb: embed deeply

verb: descend into or as if into some soft substance or place

verb: pass into a specified state or condition

verb: fall or descend to a lower place or level

verb: cause to sink

verb: fall or sink heavily

verb: go under

verb: appear to move downward